“…In contrast to our patient's subacute clinical presentation, IPF is classically associated with a more insidious onset and chronic course. [1] Our patient's convincing radiological and histopathological diagnosis of IPF was discordant with his clinical presentation, causing us to consider alternative diagnoses. His history of cave running 5 months before, although tantalising for a fungal infection, was deemed too long before presentation to be the cause in an immunocompetent individual, and was additionally excluded on both histology and culture.…”